Apparatus for bleaching cellulose and like substances



A. D. BERGLIND.

APPARATUS FOR BLEACHING CELLULOSE AND LIKE SUBSTANCES. APPucATxoN FILEDNIM/3.1918.

l p .Patented Feb. 3,1920.

2 SHEETS-SHEET l.

A. D. BERGLIND. l APPARATUS FOR BLEACHING cELLuLosE AND LlKE suBsTANcEs.

APPLICATION FILED `MAYB. 1918.

1,329,824. Peeeneed Feb. 3,1920.

2 SHEETS-SHEET 2- ANDERS DAVID BERGLIND, F KLOSTERPOSSEN,VSKIEN, NRWAY.

APPARATUS FOR BLEACI-IING CELLULOSE AND LIKE, SUBSTANCES'.

. Specification of Letters Patent.

Patented Feb. s, 1920.

Application led May 3, 1918. Serial No. 232,423.

,To all whom t may concern:

Be it known that I, ANDERS IDAvi-D BERG- LIND, a subject of the King ofSweden, re-` siding at Klosterpossen, Skien, Norway,

have invented an Improvement in Apparatus for Bleaching Cellulose andlike Substances, of which the following description, in connection withthe )accompanying drawings, is a specification, like characters on thedrawings representing like parts.

In the bleaching of cellulose and like substances with chlorin, the massis generally treated in open vats, where the air has free access and inwhich steamvisemployed to produce the desired whiteness. rl`hat herebymuch chlorin is wasted and the consumption of steam is great will easilybed understood.

It has been tried to perform the bleaching in closed vessels, but thismethod has not given the desired result, as at a certain point of theprocess air and water have to come into action in order to obtain thedesired whiteness of the mass.

The present invention has for its objectl an apparatus for bleaching,washing and lairing of the mass in a most economical According to my'process'the treatment with chlorin `is carried out in a closed vessel,and then the mass is subjected to a repeated alternate washing andairing. The apparatus employed is illustrated on the appended drawing,where vFigure 1 represents the apparatus viewed from one end showing across section of the washing and airing devices, and Fig. 2 is a sideview of the apparatus showing a longitudinal section of the saiddevices.

A is the ordinary rotating closed vessel in which the mass is treatedwith bleaching liquid, said vessel havin charging and dis- '(or both) ofthe vat is provided with a lin- .ing 2 of filtering stone through whichthe wash-wateris filtered, a chamber 3 being provided behind said liningfor collecting said water. The chamber 3 has a drain 4 I with valve 5for stopping the iow. By the arrangement of the filter stone lining 2the waste of libers is obviated. In the vat 1 is a stirrer 6 on a shaft6a, which extends outside the vat and has a cog'- wheel 6b for i powertransmission. from a motor or otherwise. 7 is a pipe extending along thetop of the vat and provided with perforations Jfor sprinkling water intothe vat. In order to increase the action of the stirrer 6 the crosssection of the bottom of the vat is semicircular corresponding to thecircumference of the stirrer 6. The bottom of the vat is inclinedtowardy one end vwhere an outlet 8 isprovided. A slide 21 is providedfor shutting o' said outlet. From the outlet 8 a pipe 9 leads to acentrifugal pump 10, and :tromthe latter a pipe 11 leads to the placewhere the product is to be used. The pipe 11 is provided with a cut-oli'valve 12 below which isvlocated a branch leading i to the airing device,the flow through which is controlled by the valve 13. i,

The airing device consists of a hoodshaped casing- 14, which is affixedto a base 14sl resting on the edge of the vat 1. The

18, said tube being at 19 connected to a fanblower 20.

The working of the apparatus is as follows:

The mass is treated in the cylinder A for i about live hours, and isythen discharged into the vat 1. The stirrer v6 is now rotated andwatery is introduced through pipe `7. During this treatment the outlet 8is closed. After the lapse of a suitable time the valve 21 is opened,the pump 10 is started, the

Valve 12 is closed and the valve 13 is now opened. The mass is now drawnthrough pipe 9 to pump 10, and thence up through` the standpipe 11,passes into the branch 1,3, and thence into the casing `14, ,where it isdistributed 'on the plate 16, and on dropping from the edge of thelatter the mass is penetrated by currents of air from. the apertures 18and drops then into the vat 1A, where it is subjected to a renewedwashing operation.

This alternate washing and airing bf the mass is carried on until themass after about two hours treatment is quite White and free from lyeand gases. y

When thewashing and airing operations are finished, the valve 13 'isshut oil and the valve l2 is opened so that the mass may be forwarded tothe-place Where it is to be used.l

What l claim as my invention is i 1; In apparatus for bleachingcellulose,

a bleaching vessel, a vat to receive bleached material, stirring meansin the vat, means for sprinkling Water into the vat, a pump, a valvedconnection between the pump and the bottom of the vat, a discharge pipeleading from the pump, and arranged to discharge material .drawn fromthe vat by the pump back into the vat, and means to force air throughsaid material as the same is discharged by the pump into the vat.

2. Apparatus for bleaching cellulose7 Lacasse comprising a vat, stirrinmeans in the vat, means to draiv material trom the bottom of the vat andto discharge the same at an elevated'point back into the vat, and meansto force air through such material as the same is discharged back intothe vat.

3. ln apparatus for bleaching cellulose, a vat, stirring means in thevat, a spreading plate arranged above the vat, means to withdrawmaterial from the bottom of the vat and `to discharge the same onto saidspreading plate so that such material falls from the spreading plateback into the vat, and means to force air through such material as thesame falls back into the vat.

In testimony whereof I have. signed my name to this specification.

ANDERS DAVD BERGLIND. Witnesses v J. W. PEDERSEN, JOH. UsLER,

